Passive initiation to alcohol during adolescence influence later voluntary alcohol consumption

FABIO M.C.; SPEAR NE; PAUTASSI RM

San Pablo

Congreso; 2011 Meeting of the Latin-American Society for Biomedical Research on Alcoholism (LASBRA); 2011

Latin-American Society for Biomedical Research on Alcoholism (LASBRA)

Background: An early onset of alcohol use, which typically   takes   place   in   early   adolescence,   is associated  with  heightened  probability  of  alcohol use  disorders  later  in  life.  Moreover,  adolescents often  engage  in  intermittent,  binge-like  alcohol consumption  that  is  associated  with  alterations  in brain  function.  The  aim  of  this  study  was  to evaluate    voluntary    alcohol    consumption    in adolescents  passively  initiated  to  alcohol  through an   intermittent   schedule.   Methods:   Adolescent Wistar  rats  received  5  [5-day  exposure  group, postnatal days (PDs) 28, 30, 32, 34 and 36], 2 (2-day  exposure  group:  ethanol  on  PD  28  and  32, vehicle on PD 30, 24 and 36) or 0 (control  group treated  with  vehicle  on  PDs  28,  30,  32  and  36) intragastric  administrations  of  alcohol  (2.5  g/kg). Locomotor  activity  was  assessed  on  PDs  28,  32 and  36,  5  minutes  after  intubations.  This  passive initiation to alcohol was followed by a 12-day-long ethanol intake protocol. During PDs 39 to 42 (two-bottle choice phase) animals had continuous, 24 h  access  to  alcohol  (concentration:  5.6%  alcohol, vehicle:  1%  sucrose;  ad-libitum  food)  and  water. Adolescents  were  then  given  standard  access  to water and food for seven days (alcohol deprivation phase, PDs 43-50). On PD 51 animals were tested in a 24 h, two-bottle choice test (5.6 % sweetened alcohol  vs  water).  Results:  Alcohol  treatment  at PD28  induced  substantial  locomotor  activity,  yet this   effect   subsided   after   repeated   treatment. Perhaps  more  important,  alcohol-initiated  animals showed  significantly  greater  alcohol  consumption at  PD  50  (i.e.,  after  the  deprivation  phase)  than non-initiated  animals.  The  facilitative  effect  of alcohol   initiation   was   significantly   greater   in animals   given   the   longest,   5-day   intermittent exposure.  There  was  no  significant  association between ethanol- or vehicle-induced motor activity at initiation and ethanol intake scores. Conclusions: Altogether,  these  results  highlight  the  permisive role of adolescent alcohol exposure on later alcohol preference.  A  brief,  binge-like  alcohol  initiation during  early  adolescence  significantly  increased alcohol consumption at late adolescence.